【作者】 石小丽；

【导师】 潘志娟；

【作者基本信息】 苏州大学 ， 纺织材料与纺织品设计， 2014， 博士

【摘要】 我国合成纤维总产量约占世界总产量的50%以上,但除涤纶、锦纶、腈纶等常规品种外,功能性纤维类型不多,特别是功能性丙纶甚少。近十几年来,我国核辐射、电子束照射和等离子体照射改性技术在聚合物改性研究中得到应用,这弥补新材料在合成技术开发方面的不足。相比较而言,紫外光引发接枝改性设备成本低,反应速度快,易于连续化操作,且穿透性小,接枝聚合可严格限定在聚合物的表面,不会损坏聚合物本体力学性能,在改善聚丙烯亲水性、吸附性与染色性有重要推广应用价值。本文基于溶液聚合和紫外引发技术,将功能性不饱和单体接枝聚合到丙纶织物表面,赋予丙纶亲水性与吸附性能。论文系统地探讨了七种不同单体(三种类型的单体)接枝聚合规律,三种不同形态结构丙纶织物和三种不同预处理方法对丙纶织物接枝率的影响及接枝织物微观结构和性能,并将接枝丙纶织物应用于模拟染料废水和重金属废水的处理,得到如下主要结论。(1)在选定实验条件下,七种单体接枝聚合的活性顺序为：MAPTAC>GMA>AA>HEMA>DADMAC>MAA-AA>MAA本质上,当单体聚合活性高、在丙纶表面润湿性好和接枝聚合链在接枝溶剂中溶胀优时,单体的接枝率高。(2)三种丙纶织物中,SMS接枝率最高,优先接枝在熔喷层。MPF接枝率最低。MAPTAC接枝使丙纶结晶度明显降低,而AA和DADMAC接枝对丙纶结晶度影响小。(3)接枝织物的润湿性与单体、织物结构及接枝聚合物的位置有关。疏水性的GMA接枝物缓慢降低水接触角；亲水性的HEMA接枝物均明显地降低水接触角。在接枝的SMS中,大量接枝的PMAPTAC形成了芯吸效应；而PAA接枝率低时仍表现疏水作用。接枝织物的水通量与织物结构及单体有关。当单位面积、单位质量织物的接枝率相同时,纺粘布水通量最大。疏水性单体接枝后织物水通量明显降低,而亲水性单体接枝后水通量降低较小。(4)经电子束照射、高能射线辐射和电晕放电预处理后,在纤维表面富集了自由基,这有利于疏水性的GMA在丙纶工业丝布表面接枝。其中,电晕放电处理效果更明显。但亲水性的HEMA和DADMAC在预处理后的接枝率提高不明显。光敏剂预浸泡、辐射预处理和丙烯酸中和等三种方法并用显著地提高了AA在丙纶工业丝布表面的接枝率,且使接枝物能均匀覆盖织物表面。(5)弱酸性红染料趋于团聚和缔合现象使低浓度染料去除率反而减小。染料分子与接枝聚合物之间较弱的作用力使吸附温度依赖性不明显。两种类型的染料分子吸附动力学和吸附平衡均分别服从Lagergren’s准二级动力学方程和Freundlich等温吸附式。在动态吸附过程中,强碱性的PMAPTAC吸附作用受小分子电解质和酸碱性等环境影响相对较小,而弱酸性的PAA受环境影响大。吸附质的尺寸效应和吸附质与吸附剂之间的作用力决定分离效果。重金属离子去除率低,但吸附量较高。尺寸大的染料分子去除率高,但吸附量低。本文特色与创新之处在于：(1)系统地探讨了(三种不同类型)七种单体或者组合对丙纶纺粘织物接枝改性的影响,结果表明：单体本身聚合反应活性、单体在纤维表面的润湿性以及接枝聚合物在接枝溶剂中溶解性是决定接枝率的主要因素。(2)系统地研究了三种丙纶织物接枝改性,结果表明：纤维的结晶度与结晶类型和纤维的线密度是决定接枝率的重要因素。(3)通过γ射线预照射、高能电子束预照射和放电预处理丙纶工业丝布和继续紫外接枝改性研究发现：三种照射方法促进了GMA接枝聚合,而对HEMA接枝无效。当预照射与预浸泡光敏剂、丙烯酸中和方法并用时,显著改善了丙烯酸接枝率。更多还原

【Abstract】 China’s synthetic fiber production accounts for ca.50%of the world’s total throughput, but the variety of functional fibers is limited. In recent years, the polymer modification techniques with y-ray, and electron-beam irradiation and plasma treatment have gained rapid progresses and found a lots of applications, which makes up for the shortage in the development of synthetic and fabrication technologies. Furthermore, the ultraviolet-irradiated graft polymerization has the features of low equipment cost, fast response, and easy operation. Particularly, the low UV penetration can strictly direct grafting to be taken place on the polymer surface, and thus does not damage the polymers. Therefore, UV grafting has already shown important application for improving the hydrophilicity and dyeability of polypropylene (PP).In this dissertation, the seven unsaturated monomers were grafted onto the surfaces of PP fabrics to improve their hydrophilicity via the UV-initiated graft copolymerization. The effects of three types of monomers, three kinds of morphologically different PP fabrics, and three different pretreatments on the grafting and the hydrophilicity of the grafted were investigated in detail. The adsorptive separation of simulated dyes and heavy metal ions waste waters were carried out. The major findings and conclusions are listed as follows.(1) The order of the graft polymerization reactivity was obtained based on the selected experimental conditions:MAPTAC> GMA> AA> HEMA> DADMAC> MAA-AA> MAAEssentially, the high reactivity, and the good wettability of the monomers on the surface of PP fibers, and the preferable solubility of the grafting polymer chains in the grafting solvent will result in a high grafting.(2) Among the three kinds of PP fabrics, SMS gave the highest degree of grafting since the inner ultrafine meltblown fiber layer soaked a large volume of grafting monomers, while the heavy monofilament MPF had the lowest. The hydrophilic monomer but the hydrophobic polymer of MAPTAC led to reduced crystallinity, whereas the twin hydrophilicity of monomer and polymer was no effect on crystallinity.(3) The water wettability of the grafted depends on the grafted polymer component, and fabric structure. The water contact angle of hydrophobic GMA grafts slowly reduced with grafting, while that of hydrophilic HEMA grafts decreased significantly. Although the grafting of hydrophilic AA and MAPTAC prefered to happen in the melt-blown layer in SMS, a lot of MAPTAC grafts produced wicking, whereas the low grafting AA still presented hydrophobic. Graft modification reduced the water flux of the fabrics, and the fluxes of the grafted rely on the fabric structure and the grafted polymer components. When the actual degree of grafting is equivalent to the theoretical degree of unit area and unit mass, the spun-boned fabrics have the largest fluxes. The hydrophobic grafting polymers caused a remarkably decreased flux whereas the hydrophilic polymer led to a trivial reduction.(4) The semi-crystalline PP fiber surface enriched free radicals after the electron-beam, and y-ray irradiation and the corona discharge pretreatment respectively, which significantly promoted the grafting of the hydrophobic GMA, with no effect on the grafting of hydrophilic HEMA and DADMAC. Among them, the corona discharge pretreatment is the most effective. The combination of radiation pretreatment, pre-soaked photo-sensitizer and neutralization of acrylic acid significantly improved the grafting of the PP monofilament cloth with uniformly thin layer covered.(5) It is the weak acid red aggregation that low initial dye concentration resulted small dye removal unexpectedly. Weak interaction between the dye molecules and grafted polymers led to the adsorption insensitivity towards temperature. Two kinds of dye molecules’adsorption kinetics and equilibrium obeyed Lagergren’s quasi-second-order kinetic equation and Freundlich isotherm respectively. The adsorption of strong alkaline polyelectrolyte PMAPTAC wasn’t interfered by small molecule electrolyte and acidity, vice verse for weak acidic poly(acrylic acid). The filtration results of simulated heavy metal ions and dyes wastewaters showed that the size of adsorbate, and the force between adsorbate and adsorbent determine the separation efficiency. The removal of heavy metal ions was low, but the adsorption capacity was high, vice verse for the dye molecules. This features and innovations of the dissertation include:(1) The comprehensive UV-grafting polymerization was carried out on the spun-bonded PP nonwovens, and the results indicated that monomer reactivity, the wettability of the monomer on the fiber surface and the solubility of the grafting polymer chains in solvent dominate the grafting.(2) The graftability of five kinds of polypropylene was investigated, and the results showed that fiber crystallinity, the type of crystalline, and fiber fineness are determining factors for grafting.(3) The grafting polymerization of monofilament fabric with the three pretreatments of y-ray, and electron-beam irradiation and corona discharge was studied, and the results demonstrated all pretreatments promote the grafting of hydrophobic glycidyl methacrylate onto the monofilament PP fabric. The combination of the pre-irradiation, the pre-soaking of photosensitizer and neutralization of acrylic acid improve significantly grafting.更多还原